25.10.18 09:31, Ronie Martinez пише:
Here is an example:
import itertools
import time
def main():
datetime_odometer = itertools.product(
range(2018,10_000),# year
range(1,13),# month
range(1,31),# days
range(0,24),# hours
range(0,60),# minutes
range(0,60)# seconds
)
datetime_of_interest = (2050,6,15,10,5,0)
for iin datetime_odometer:
if i == datetime_of_interest:# target start time
break
if __name__ =='__main__':
start = time.time()
main()
duration = time.time() - start
print(duration,'seconds')# 91.9426908493042 seconds
It took 92 seconds to get to the target start time. It does not only
apply to datetimes but for other purposes that uses "odometer-like"
patterns.
I don't have any propose solution for now, but I guess adding this
feature within itertools will come in handy.
Thank you for clarification. Now I understand your idea.
For datetimes it is better to use the datetime classes:
def iterdatetimes():
delta = timedelta(microseconds=1)
dt = datetime(2050,6,15,10,5,0)
while True:
yield dt
dt += delta
Note that in your example you missed 31th days, but iterate 29th and
30th February.
See also the calendar module which provides date range iterators
(although not with microsecond precision).
Currently for general "odometer-like" patterns you can use the
undocumented __setstate__ method of itertools.product. But this is on
your own risk.
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